Recently, it has been very important to improve fuel efficiency when a vehicle is driving on actual road since consumer complaints have increased due to the difference between authorized fuel efficiency and actual road-driving fuel efficiency. Therefore, the automobile industry has studied and developed the technology that maximizes the fuel efficiency by using driving conditions of a driver, around traffic situations and road information, etc. during a vehicle is driving on actual road as well as controls a vehicle system.
As examples, the technology searching and guiding an economical driving route by utilizing IT (Information Technology) and traffic information, the technology guiding effective fuel efficiency driving by memorizing slope information of running road and past running patterns, the technology controlling charging/discharging of a battery according to the level of SOC (State Of Charge) of the battery by predicting and determining road slope and traffic information, the technology controlling driving modes selectively in order for the fuel consumption to be minimized based on destination route and traffic information by using Map information DB (Data Base) have been studied and developed.
As stated above, as one technology among the technologies maximizing the fuel efficiency, there is Start/Stop Coasting (SSC). FIGS. 1A and 1B are drawings explaining SSC. Referring to FIG. 1A, SSC is a technology that cuts off fuel supply (Fuel Cut) and blocks the power transmission of a transmission during coasting (Clutch Off). According to this, an engine drag torque is blocked so that a driving distance may be increased compared to the conventional vehicle that does not have SSC capabilities (refer to FIG. 1B).
In the prior art, however, there is only the function recognizing present driving states as entry requirements of SSC but not recognizing driving conditions of road sections ahead of the current position of the vehicle. Accordingly, the SSC is applied when a driver does not step on an accelerator pedal before entering into quick turning road, and the SSC is released when the driver steps on a brake pedal in order to decelerate a vehicle after entering into the quick turning road. As stated above, since the SSC is frequently applied in the prior art, there is the problem that the durability of the components associated to the SSC is falling.